Corner flashing

ABSTRACT

A corner flashing assembly for providing a moisture barrier at corners at the base of a foundation wall. The corner flashing assembly according to the invention comprises an upper corner piece and a lower corner piece. The upper and lower corner pieces are dimensioned such that, when installed, the lower edge of the upper corner piece and the upper edge of the lower corner piece overlap a certain distance, thereby allowing adjustability to accommodate varying dimensions of construction blocks, yet providing an effective moisture barrier. Portions of the corner pieces that will come into contact with mortar are coated with asphalt to improve the adherence of the mortar to the flashing.

BACKGROUND INFORMATION

1. Field of the Invention

The present invention relates to the field of flashing for the buildingindustry. More particularly, the invention relates to corner flashing toseal corners at the base of foundation walls.

2. Description of the Prior Art

The use of flashing to protect buildings against water damage iswell-known in the construction industry. Some areas of roofs andexterior walls are prone to leaks and water damage. These areas includean intersection between a chimney or window and a roof surface.Flashing, generally formed from a thin sheet of water-impermeablematerial, is used to protect a structure from damage by water. Edvardsen(U.S. patent appl. Pub. 2004/0103592 A1) discloses a two-part roofflashing kit for a roof-penetrating structure with two flashing portionsthat are adjustable to allow for use with roof penetrating structures ofvarying dimensions. Each of the two parts has a fold of material and thetwo parts are adjustably coupled with slidingly engaging the two folds.The disadvantage of the Edvardsen flashing is that the double foldrequires additional material and fabrication time and provides greaterbulk when the flashing is installed.

It is also well-known to use flashing to provide a moisture barrier atthe base of foundations, particularly at the corners of foundationswhere water often collects, and beneath windows and doors. It isstructurally and aesthetically important that the corner flashing fitproperly for its intended use, that is, the lower horizontal portion lieflush on the foundation base, the vertical portion cover precisely thefirst two courses of blocks at the base of the foundation, and the upperhorizontal portion then fit over the top edge of the upper block of thetwo courses, without buckling or leaving gaps. Because the dimensions ofconstruction blocks typically used to construct foundation walls varyslightly from manufacturer to manufacturer, corner flashing istraditionally custom-fabricated off-site for a particular constructionjob, a costly and time consuming process. Pre-cast corner flashing isknown, but it has a disadvantage in that it is not adjustable to thevarying heights of construction blocks.

What is needed, therefore, is a corner flashing assembly that provides awater-impermeable seal around a corner at the base of a foundation walland is easily adjustable to accommodate variations in the dimensions ofconstruction blocks. What is further needed is such a corner flashingassembly that is easily and economically manufactured.

BRIEF SUMMARY OF THE INVENTION

For the reasons stated above, it is the object of the present inventionto provide a corner flashing assembly that provides a water-impermeableseal around the corner at the base of a foundation wall that is easilyadjustable to accommodate variations in the dimensions of constructionblocks. It is a further object to provide such a corner flashingassembly that is easily and economically manufactured.

The objects of the invention are achieved by providing a corner flashingassembly that fits neatly around the inside or outside corner of abuilding wall. The corner flashing assembly according to the inventioncomprises an upper corner piece and a lower corner piece. Each cornerpiece is shaped such that it neatly fits around the contour of thecorner and has a vertical and a horizontal section. The horizontalsection of the lower corner piece provides an apron on the foundationbase at the base of the corner; with the vertical section extendingupward over the wall face of perhaps two courses of construction blocks.The horizontal section of the upper corner piece is placed on the topface of the upper block of the two courses, with its vertical sectionextending downward over the face of the construction blocks. Thevertical section of the upper corner piece overlaps a portion of thevertical section of the lower corner piece. This overlap is great enoughto allow adjustability and also, barring catastrophic flooding, toprevent moisture seeping in between the upper and lower corner pieces.

The corner flashing assembly is made of copper. Copper is a desirablematerial for use in flashing because it is water-impermeable, it forms aprotective patina in the presence of oxygen that is desirable and hasaesthetic appeal, and, most importantly, does not corrode under theinfluence of the acids and alkalines that are present in conventionalconstruction materials. Ideally, sections of the corner flashingassembly that will come into contact with mortar are coated with anasphalt coating, which improves the adhesion of the mortar to thecopper.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described with reference to the accompanyingdrawings. In the drawings, like reference numbers indicate identical orfunctionally similar elements.

FIG. 1 is a perspective view of a first embodiment of the cornerflashing according to the invention.

FIG. 2 is a perspective view of a second embodiment of the cornerflashing according to the invention.

FIG. 3 is a side view of the upper corner overlapping the lower cornerof the corner flashing.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates the first embodiment of a corner flashing assembly100 that protects an outer corner C_(O) at a foundation base B of afoundation wall W against water and moisture. The corner flashingassembly 100 comprises a lower corner 110 and an upper corner 120. Thelower corner 110 is constructed as a single piece of copper materialthat includes a lower vertical section 111 that wraps around the outercorner C_(O), a lower horizontal section 114 that forms a flat apron onthe foundation base B, and a lower vertical fold 118 that extends alongthe lower vertical section 111. Forming the lower corner 110 byvertically folding a single sheet of material creates a corner gap 135in the lower horizontal section 114 that is bounded by a left edge 115and a right edge 116. A gap panel 145, i.e., a flat square piece ofcopper, is soldered to the left edge 115 and right edge 116 to form acontinuous, gapless horizontal surface that, when the lower corner 110is installed, forms a flat apron along the foundation base B and aroundthe corner C_(O).

The upper corner 120 is also constructed as a single piece of copperthat includes an upper horizontal section 121, an upper vertical section124, and an upper vertical fold 128. Ideally, the upper horizontalsection 121 is formed from a single sheet of material by making a90-degree fold in the sheet to create the upper vertical fold 128. Anupper section of the sheet is then folded perpendicular to the uppervertical section 124, to form the upper horizontal section 121. Thisfold creates an excess of material at a corner fold section 122. Tofacilitate this operation, a cut may be made in the upper section andsome of the excess material removed. The material may be folded,trimmed, and/or soldered to form a gapless seam with the appropriategeometry to fit neatly around the outside corner C_(O).

To install the corner flashing assembly 100, the lower horizontalsection 114 is placed on the foundation base B, with the lower verticalfold 118 flush around the outer corner C_(O). The upper horizontalsection 121 is then placed along the top face of a construction blockB_(T) at the outer corner C_(O) of the foundation wall W, with the uppervertical section 124 extending downward and and overlapping a portion ofthe lower vertical section 111, creating an overlap barrier 150. Onceinstalled, a layer of mortar and another course of construction blocksis placed on top of the upper corner 120, securing and sealing it inplace. Later, when flooring is installed, mortar will be applied to theapron formed by the lower horizontal section 110, thereby securing andsealing that portion of the flashing assembly 100.

FIG. 2 illustrates a second embodiment of the corner flashing assembly200 that protects an inside corner C_(I) at the base of a foundationwall W. The corner flashing assembly 200 comprises a lower corner 210and an upper corner 220. The lower corner 210 is constructed from asingle piece of copper material that includes a lower vertical section211 that fits within the inner corner C_(I), a lower horizontal section214 that lies flat on the foundation base B, and a lower vertical fold218 that extends along the lower vertical section 211. The lowervertical fold 218 is formed by creating a 90-degree fold along thevertical axis of the lower vertical section 211. The lower horizontalsection 214 is then formed by folding a portion of the sheetperpendicular to the lower vertical section 211. This second foldcreates an excess of material in the lower horizontal section 214. Theexcess material may be folded and trimmed to form the square lowerhorizontal section 214. Ideally, the material is folded and only theouter edges are trimmed so as to create a surface that is water-tight,yet has no ragged edges. It is, of course, possible to trim some of theexcess material and then to solder the edges of the cut together tocreate a water-tight surface, or to trim some excess material, fold theremaining material to create a water-tight seal, and/or to solder thefolded edge.

The upper corner 220 is also constructed as a single piece of copperthat includes an upper horizontal section 221, an upper vertical section224, and an upper vertical fold 228. As in the first embodiment, theupper horizontal section 221 is ideally formed from a single sheet ofmaterial by making a 90-degree fold in the sheet of material. This formsthe upper vertical fold 228 that fits into the inner corner C_(I). Thenan upper portion of the material is folded perpendicular to the verticalplane, forming the upper vertical section 224. This creates a corner gap235 bounded by a left edge 222 and a right edge 223. A gap panel 245 issoldered to the left edge 222 and the right edge 223 to form acontinuous, gapless horizontal surface that, when the upper corner 220is installed, fits neatly over the top face of a construction blockB_(T) and into the inner corner C_(I) of the foundation wall W.

FIG. 3 illustrates the adjustability of the corner flashing assembly100. The upper horizontal section 121 of the upper corner 120 is placedalong the top face of a construction block B_(T), with the uppervertical section 124 extending downward and flush about the outer cornerC_(O) and overlapping the lower vertical section 111 to form the overlapbarrier 150. The amount of overlap at the overlap barrier 150 issufficient to accommodate the dimensional variability of conventionalconstruction blocks, yet still provide a barrier against the ingressionof water.

The preferred embodiments of the invention 100, 200 are constructed ofcopper. Ideally, a coating of asphalt is applied to all areas that willcome into contact with mortar, as the asphalt improves the adhesion ofmortar to copper.

It is understood that the embodiments described herein are merelyillustrative of the present invention. Variations in the construction ofthe flashing assemblies may be contemplated by one skilled in the artwithout limiting the intended scope of the invention herein disclosedand as defined by the following claims.

1. Flashing for sealing a foundation wall constructed of constructionblocks, said foundation wall including a corner that intersects with afoundation base, said flashing comprising: a lower corner having a lowervertical section with a lower vertical fold that extends along saidlower vertical section and forms a 90-degree vertical corner fold, and alower horizontal section that extends from and perpendicular to saidlower vertical section; an upper corner having an upper vertical sectionwith an upper vertical fold that extends along said upper verticalsection and forms a 90-degree vertical corner fold, and an upperhorizontal section that extends from and perpendicular to said uppervertical section; wherein said upper vertical section and said lowervertical section are adapted to provide a single layer overlap of alowermost portion of said upper vertical section over an uppermostportion of said lower vertical section when installed on said foundationwall.
 2. The flashing of claim 1, wherein said lower corner and saidupper corner are constructed of copper.
 3. The flashing of claim 1,wherein said lower horizontal section is coated with asphalt.
 4. Theflashing of claim 1, wherein said upper horizontal section is coatedwith asphalt.
 5. The flashing of claim 1, wherein said corner of saidfoundation wall is an outer corner and said lower horizontal sectionincludes a gap panel that is attached to said lower corner to form awater-impermeable, continuous surface of said lower horizontal section.6. The flashing of claim 1, wherein said corner of said foundation wallis an inner corner and said lower horizontal section is formed byfolding and trimming a lowermost portion of said lower vertical section.